摘要 |
A rotating control device for sealing about a drill string having a change in outer diameter can include a seal which rotates with the drill string, the seal including at least two chambers connected by a passage, and a fluid which flows between the chambers via the passage in response to displacement of the outer diameter change through the seal. A method of sealing can include forming at least two chambers in a resilient material of a seal, displacing the outer diameter change into the seal, thereby transferring fluid from a first chamber to a second chamber, and displacing the outer diameter change out of the seal, thereby transferring the fluid from the first chamber to the second chamber. One of the chambers can increase in volume while the other of the chambers decreases in volume. |